math

y =  x+5 

Sub this value of y into the second equation:

x+5 = -2x-1   solve for x   ====> add  2x to each side

3x + 5 = -1    subtract  5 from each side

3x = -6

x = -2        NOW, sub this into one of the first two equations to find 'y'

y = x+5

y = -2 + 5  = 3

y = x + 5

y = -2x - 1

Set the y's equal

x + 5  = - 2x - 1        subtract x, add 1 from/to each sides

6 = - 3x              divide both sides by - 3

-2 = x

And using  y = x + 5

y = - 2 + 5

y = 3

(  -2, 3)  = (x , y)